This invention pertains to thermostat arrangements for thermoelectric refrigerators, and in particular to thermostat arrangements having a first order response characteristic. Thermoelectric refrigerator devices have found wide acceptance in a variety of applications including miniature electronic circuits, temperature controls, and medical and laboratory instrumentation. Frequently, it is required to maintain the temperature of an object to be cooled within close tolerances. One such requirement arises in the superconducting electronic art, where thermal noise of very sensitive electronic devices is a limiting design and operation factor. Conventional temperature regulation systems include open loop, and feedback control systems. The open loop system typically contains a transformer and rectifiers, while feedback systems typically contain thermistors which sense the temperature of the control junction of the thermoelectric refrigerator device. While the feedback systems offer closer temperature regulation and faster response times than the open loop control systems, superior control systems are needed. In particular, no first order control systems, i.e. those systems in which the first derivative of the control current with respect to temperature is infinite, are known. Such control is especially needed for superconducting microelectronics such as superconducting quantum interference devices, where Johnson or thermal noise of the microelectronic devices is proportional to the temperature fluctuation of the device.
It is therefore an object of the present invention to provide a thermostat arrangement for superconductor devices having improved temperature regulation and response time.
Another object of the present invention is to provide a thermoelectric refrigerator with a thermostat arrangement having a first order response characteristic, one in which the first derivative of the thermoelectric property with respect to temperature is infinite.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.